Vehicle electrical-load limiting apparatus

Abstract

A vehicle electrical-load limiting apparatus wherein the priority given over a plurality of electrical loads, for restricting the driving of the electrical loads mounted on a vehicle, is first decided in order of importance and the amount of drive restriction of each of the electrical loads is then determined based on the remaining capacity of a vehicle electric source, thereby restricting the driving of the electrical loads. A fuzzy inference is carried out by making use of membership functions corresponding to both (a) the deviation indicative of the difference between a standard value set for each electrical load attached to the vehicle and a value of an electrical load when now in use, and (b) the residual capacity of the electric source. Then, the amount of the drive restriction of each of the electrical loads is obtained from the result of the fuzzy inference. It is therefore possible to automatically determine to what degree the driving of the electrical loads should be restricted according to the degree of the residual capacity of the electric source.

What is claimed is: 
     
       1. An apparatus, for deciding priority given over a plurality of electrical loads and restricting the driving of said electrical loads mounted on an electric vehicle in order of importance and determining the amount of drive restriction of each of said electrical loads on the basis of the remaining capacity of an electric source mounted on the electric vehicle, thereby restricting the driving of each of said electrical loads, said apparatus comprising: arithmetic means for setting membership functions corresponding to both (1) a deviation indicative of the difference between a standard value set for each of said electrical loads and a present value indicative of the state of the present electrical load and (2) the remaining capacity of said electric source and executing a fuzzy inference using said membership functions, thereby determining the amount of the drive restriction of each of said electrical loads from the result of the execution of said fuzzy inference;   wherein said arithmetic means comprises: (a) restriction priority setting means for setting said drive restriction priority of said plurality of electrical loads mounted on the vehicle in order of importance;   (b) restriction priority storing means for storing therein said set drive restriction priority of said plurality of electrical loads;   (c) electrical load detecting means for detecting one of said plurality of electrical loads;   (d) standard value arithmetic means for performing an arithmetic operation on a standard value of a desired electrical load based on the present value of said detected one electrical load;   (e) deviation arithmetic means for calculating the deviation indicative of the difference between the present value of said detected one electrical load and said calculated standard value of said desired electrical load;   (f) residual-capacity detecting means for detecting the remaining capacity of an electric source mounted on the vehicle;   (g) fuzzy inference arithmetic means for reading a membership function of the deviation and the residual capacity, which has previously been stored in membership function storing means on the basis of said calculated deviation and said detected residual capacity and performing an arithmetic operation on a fuzzy inference based on said read membership function;   (h) amount-of-drive-restriction arithmetic means for calculating the amount of the drive restriction of each of said electrical loads from the result of the arithmetic operation on said fuzzy inference; and     (i) electrical-load controlling means for reading said drive restriction priority stored in said restriction priority storing means based on the result of the arithmetic operation on said amount of the drive restriction and controlling each of said electrical loads in accordance with said drive restriction priority; and   wherein said electrical loads whose drive restriction priority is stored in said restriction priority storing means are divided into a first group unsuitable to the drive restriction of said electrical loads, a second group capable of adjusting the amount of the drive restriction of each of said electrical loads, a third group capable of adjusting the amount of the drive restriction of each of said electrical loads and providing economical use of said electrical loads in accordance with use environments of the vehicle, and a fourth group suitable to the drive restriction of said electrical loads and incapable of adjusting the amount of the drive restriction of each of said electrical loads.   
     
     
       2. An apparatus according to claim 1, wherein said first group includes electrical loads such as a power steering and a running-motor controller or the like, which are indispensable to the running of the vehicle. 
     
     
       3. An apparatus according to claim 1, wherein said second group includes electrical loads such as an air conditioner and a heater coil or the like, which are capable of restricting performance of said electrical loads by reducing electric power to be supplied. 
     
     
       4. An apparatus according to claim 1, wherein said third group includes electrical loads capable of restricting their performance by reducing supply power, and economically avoiding unnecessary operations such as wiper driving at the time of stoppage of the vehicle and control of the turning on of a headlight at a bright location. 
     
     
       5. An apparatus according to claim 1, wherein said fourth group includes electrical loads such as an interior light and a remocon mirror or the like, which are incapable of adjusting the amount of the drive restriction of each of said electrical loads when they are subjected to a use limit. 
     
     
       6. An apparatus according to claim 1, wherein said electrical load detecting means is a detecting circuit for detecting the total dissipated power of various electrical components mounted on the vehicle. 
     
     
       7. An apparatus according to claim 1, wherein said residual-capacity detecting means includes depth-of-discharge detector for detecting the depth of discharge of a vehicle driving battery and an arithmetic circuit for calculating the remaining capacity of the battery based on said detected depth of discharge. 
     
     
       8. An apparatus according to claim 1, wherein said fuzzy inference arithmetic means has a membership function storing circuit for storing therein a membership function of the deviation and the residual capacity which have been set in advance. 
     
     
       9. An apparatus according to claim 1, wherein said fuzzy inference arithmetic means is activated to divide a membership function relative to the residual capacity read from said membership function storing means into a plurality of fuzzy regions in accordance with the depth of the discharge. 
     
     
       10. An apparatus according to claim 1, wherein said amount-of-drive-restriction arithmetic means performs an arithmetic operation on the amount of the drive restriction based on values of the membership functions relative to the deviation and values of the membership functions relative to the residual capacity. 
     
     
       11. An apparatus according to claim 1, wherein said arithmetic means automatically calculates a standard value in accordance with an environmental state to which the vehicle is subjected. 
     
     
       12. An apparatus according to claim 11, wherein an arithmetic operation on said environmental state is performed based on a detected signal output from each of a luminance sensor, a moisture sensor and a temperature sensor. 
     
     
       13. An apparatus according to claim 1, wherein said vehicle is an electric automobile. 
     
     
       14. An apparatus, for deciding priority given over a plurality of electrical loads for restricting the driving of said electrical loads mounted on a vehicle in order of importance and determining the amount of drive restriction of each of said electrical loads on the basis of the remaining capacity of an electric source mounted on the vehicle, thereby restricting the driving of each of said electrical loads, said apparatus comprising: arithmetic means for setting membership functions corresponding to both the deviation indicative of the difference between a standard value set for each of said electrical loads and the present value indicative of the state of the present electrical load and the remaining capacity of said electric source, and executing a fuzzy inference using said membership functions, thereby determining the amount of the drive restriction of each of said electrical loads from the result of the execution of said fuzzy inference;   said arithmetic means comprising restriction priority setting means for setting said drive restriction priority of said plurality of electrical loads mounted on the vehicle in order of importance, restriction priority storing means for storing therein said set drive restriction priority of said plurality of electrical loads, electrical load detecting means for detecting one of said plurality of electrical loads, standard value arithmetic means for performing an arithmetic operation on a standard value of a desired electrical load based on the present value of said detected one electrical loads, deviation arithmetic means for calculating the deviation indicative of the difference between the present value of said detected one electrical load and said calculated standard value of said desired electrical load, residual-capacity detecting means for detecting the remaining capacity of an electric source mounted on the vehicle, fuzzy inference arithmetic means for reading a membership function of the deviation and the residual capacity, which as previously been stored in membership function storing means on the basis of said calculated deviation and said detected residual capacity and performing an arithmetic operation on a fuzzy inference based on said read membership function, amount-of-drive-restriction arithmetic means for calculating the amount of the drive restriction of each of said electrical loads from the result of the arithmetic operation on said fuzzy inference, and electrical-load controlling means for reading said drive restriction priority stored in said restriction priority storing means based on the result of the arithmetic operation on said amount of the drive restriction and controlling each of said electrical loads in accordance with said drive restriction priority; and   wherein said standard value arithmetic means performs an arithmetic operation on a standard value of each electrical load based on the final standard load value, the average value of normal electrical loads necessary for vehicle running and each of coefficients of electrical loads of the heater and the air conditioner, an electrical load of the headlight and an electrical load for driving the wipers.   
     
     
       15. An apparatus according to claim 14, wherein said arithmetic means automatically calculates a standard value in accordance with an environmental state to which the vehicle is subjected. 
     
     
       16. An apparatus according to claim 15, wherein an arithmetic operation on said environmental state is performed based on a detected signal output from each of a luminance sensor, a moisture sensor, and a temperature sensor. 
     
     
       17. An apparatus according to claim 14, wherein said vehicle is an electric automobile.